1. Field of the Invention
This invention relates to replaceable liquid reservoirs and more particularly to reservoirs which are provided with capillary type liquid delivery systems for delivering liquid from within a reservoir to a vibrating atomizer plate located above the reservoir.
2. Description of the Related Art
U.S. Pat. Nos. 4,301,093 and 5,657,926 show vibrating plate atomizers in which a reservoir is held beneath a piezoelectrically driven vibratory atomization plate. A capillary type liquid delivery system, comprising a fabric wick, extends up from within the reservoir to a location under the vibrating atomization plate to deliver liquid from within the reservoir to the underside of the plate to be atomized thereby.
U.S. Pat. No. 5,518,179 also shows a vibratory type atomizer in which liquid from a fluid source is delivered by a foam capillary material which is lightly compressed against a vibratory perforate membrane. The perforate membrane is shown to be located in a vertical plane; and the foam capillary material is shown to extend upwardly from the fluid source and to be bent through 90xc2x0 so that its upper end rests flat against the face of the perforate membrane.
Other atomizing devices which atomize liquids from a reservoir by means of a vibrating plate and which use a liquid delivery system to transfer the liquid from the reservoir to the plate are shown in U.S. Pat. Nos. 4,294,407, 4,479,609, 4,790,479, 4,793,339, 5,297,734, 5,299,739 and 5,996,903.
It is often necessary or desirable to orient the vibratory orifice plate of an atomizer device so that it ejects atomized or aerosolized liquid droplets at an angle to the vertical. For example, where the atomization device is to be mounted on a wall, the ejected liquid droplets should be directed away from the wall so that they do not collect and do damage to the wall surface. This problem can be overcome by orienting the vibratory perforate membrane or orifice plate so that its plane is tilted from the horizontal and away from nearby walls or other vertical surfaces.
A problem occurs when liquid is to be transferred by capillary action from a reservoir to a vibrating perforate membrane or vibrating orifice plate which does not extend in a horizontal plane. In the past, the liquid delivery systems of vibratory type atomization devices, which usually comprised a fabric wick or a solid capillary element, exited from the reservoir in a vertical direction and then became bent at a location above the reservoir so that the upper end of the capillary element terminated flat against the surface of the perforate membrane or orifice plate. As a result, there was a tendency for liquid to drip from the capillary element and accumulate outside the reservoir without being atomized or recoverable. Also where the liquid is aggressive, for example in the case of many liquid fragrances or insecticides, such leakage of the liquid can damage the surfaces on which it accumulates.
According to one aspect of the invention there is provided a novel atomizer for ejecting small liquid droplets into the atmosphere. This novel atomizer comprises a housing, a vibratory orifice plate which extends in a plane and which is mounted in the housing with its plane tilted from the horizontal. The orifice plate has a plurality of small orifices formed in its center region. A vibratory actuator is coupled to the orifice plate for causing it to vibrate rapidly in a direction perpendicular to its plane.
A replaceable liquid reservoir is removably mounted within the housing below the orifice plate. The reservoir comprises a liquid container for containing a supply of liquid to be atomized; and it further comprises a solid, porous and dimensionally stable elongated liquid delivery member. The liquid delivery member extends up along a vertical axis from a location within and near the bottom of the liquid container and through an upper opening in the container to a location above the container. The liquid delivery member has an upper end which is located above the container and which forms an upper liquid delivery surface. The liquid delivery surface itself is tilted from the horizontal and it is positioned in the housing such that it lies along the plane of the orifice plate. As a result, maximum area of contact and maximum effectiveness of liquid transfer is achieved between the liquid delivery surface and the orifice plate. The liquid delivery surface at the upper end of the liquid delivery member is also contained within and does not extend beyond the extent of the horizontal cross-section of the liquid delivery member. Consequently any excess liquid which comes off the edge of the liquid delivery surface, merely runs back along a vertical side surface of the liquid delivery member and back into the liquid container without dripping onto nearby surfaces outside the container.
According to another aspect of the invention, there is provided a novel replaceable liquid reservoir for use with a vibrating orifice plate atomizer device. This novel reservoir comprises a liquid container for containing a supply of liquid to be atomized and a solid, porous and elongated, dimensionally stable, liquid delivery member which extends along a vertical axis from within the liquid container and out through an upper opening of the container to a location along the vertical axis above the liquid container. The liquid delivery member is formed with an upper end which is located along the vertical axis and above the container. The upper end of the liquid delivery member is formed as a liquid delivery surface which intersects and forms an acute angle with the vertical axis. Thus the liquid delivery surface can lay flat against a tilted orifice plate within an atomizer device to provide maximum effectiveness of liquid transfer to the tilted orifice plate. Further, the liquid delivery surface is contained within and does not extend beyond the edge of a horizontal cross-section of the liquid delivery member. Consequently excess liquid which flows from the edge of the liquid delivery surface, merely runs back along a vertical side surface of the liquid delivery member and back into the liquid container without dripping onto nearby surfaces outside the container.